1. Field of the Invention
The present invention relates to granular stabilizers for a polymer and a production process thereof.
2. Description of the Related Art
As a stabilizer for a polymer, which stabilizes a polymer such as polybutadiene against heat and the like, 2-[1-(2-hydroxy-3,5-di-t-pentylphenyl)ethyl]-4,6-di-t-pentylphenyl acrylate (hereinafter referred to as “a compound (1-1)”), shown by the formula (1-1):
is known (see JP-A No. 1-168643).
As a process for producing polybutadiene blended with a stabilizer for a polymer, a process in which polymerization is performed in a hydrocarbon medium, and a solution comprising the polybutadiene after finishing the polymerization reaction is mixed with a solution of a stabilizer for a polymer in a hydrocarbon medium, followed by removal of the hydrocarbon medium, is generally adopted (see JP-A No. 1-168643).
Also, as a process for producing the compound of the formula (1-1), a process in which bisphenol and acrylic acid are reacted in an organic medium, and the reaction mass is washed with water and cooled to produce a crystal (see JP-A No. 1-168643), and a process in which the organic medium is distilled away by evaporation from the above-mentioned reaction mass, and methanol is added to the resulting mass to produce a crystal (see JP-A No. 4-264051) are disclosed.